The review above is great, thanks. It's right that the scene depicts a set of values I subscribe to but takes them to an extreme to make a point. And watching the clips again did make me laugh But I'm still a little uncomfortable that the film is about depicting families that the main characters reject as bad, crazy, etc.

E.g. Is sleeping in the same bed as my child really as bad as criticising his appearance within earshot? While I believe my parenting style is better for me and my child, I don't think anyone should be rude towards their children! So I still find the film confronting because it suggests it is as bad.